Federal tax burden becomes more progressive in last 25 years

according to Greg Mankiw's analysis of CBO data:

Format is { Household income: 2005 rate (1979 rate) }:

Lowest quintile: 4.3 (7.2)
Second quintile: 9.9 (13.2)
Middle quintile: 14.2 (17.1)
Fourth quintile: 17.4 (20.1)
Highest quintile: 25.5 (26.1)

Top 10 percent: 27.4 (27.6)
Top 5 percent: 28.9 (29.0)
Top 1 percent: 31.2 (31.7)

Notice that all groups are paying lower tax rates than the historical average. But in contrast to some popular perceptions, the change is not concentrated among the upper income groups. In fact, the opposite is true.